- Agronomic: general grain crops, grass (misc. perennial), hay
- Animal Production: feed/forage
- Crop Production: no-till, tissue analysis
- Production Systems: general crop production
Perennial crops that live for many years increase sustainability by holding soil, reducing nutrient runoff, limiting pesticide use, and boosting farmer incomes through a decrease in inputs. All commonly grown grain crops are annuals, but we are working to develop intermediate wheatgrass (IWG), which has potential to become the first widely grown perennial grain crop.
This project will develop improved IWG plants and determine the effect of nitrogen fertility on sustained grain yield in IWG.
We are conducting a participatory plant breeding program that includes growing IWG on college campuses, on an NGO research station in Kansas, and at a commercial nursery in Wisconsin in order to identify superior genotypes. Through cross-pollination, we are combining several important traits that we have discovered: large seed, shortness, and shatter resistance. To answer the key question of the role of soil nitrogen (N) in sustained yield, a range of N addition treatments have been applied to IWG stands on three on-farm fields and at research stations in Kansas and Minnesota. Plant tissue nitrogen and seed yield traits are being measured.
Results from the proposed research will be published in peer-reviewed journals, reported to the scientific community through seminars, published in the popular press (web and hard copy), and presented to several hundred yearly visitors to The Land Institute.
Annual grain crops comprise a large and essential portion of the human diet, but the large-scale production of grains required to meet human food needs inevitably results in soil erosion, nutrient loss and subsequent contamination of waters, and pesticide contamination. Organic and no-till practices are among the most sustainable approaches to small grain production. However, organic systems depend on tillage for weed control and can experience soil loss through erosion and nitrogen loss through leaching into groundwater. No-till small grain systems require herbicides and often allow leaching of high levels of nitrogen into groundwater. Unfavorable weather and other uncontrollable factors often disrupt methodologies that rely on cover crops, rendering such approaches unreliable. As a perennial small grain crop, IWG would drastically reduce nitrogen loss by leaching, soil loss through erosion, and the need for tillage or herbicides for weed control. This potential comes at a time when farmers’ input costs are at an all-time high and nitrogen contamination of ground and surface waters is a serious issue facing society. Intermediate wheatgrass is an obvious choice for domestication because 1) a population is available that has already experienced a decade of selection for grain production by a joint Rodale Institute–USDA project, 2) it is widely adapted, and 3) cultural techniques have been developed in the forage-grass seed industry.
- The importance of sustainable grain production. In Kansas, 60% of gross farm income comes from the sale of grain crops (USDA-NASS, 1997). Globally, more than two-thirds of all cropland is dedicated to annual grain crops (FAO, 2003). Although land currently producing grains fed to livestock could be converted to pasture, annual crops grown for human consumption will remain important in the North Central Region and internationally. In 2004, wheat was planted on 29 million acres in the North Central Region, producing 1.1 billion bushels worth $3.7 billion (USDA-NASS, 2004). A sustainable supply of small grains is critical—the average American consumes about 83 kg of wheat per year (FAO, 2002).
- Soil Erosion. Although soil erosion has been recently reduced in the U.S., most of the improvement has come through taking land out of grain production rather than improving production practices. Conversion of highly erodable land to perennial cover (CRP) reduces soil erosion by an average of 17.2 tons acre-1 year-1, whereas better management of annual crops had only reduced erosion by 2.8 tons acre-1 year-1 between 1982 and 1992 (Uri, 2001). In other words, conversion to perennials is up to six times as effective at controlling erosion as is improved management of annual crops. Despite progress, soil erosion remains a major problem, causing the U.S. an estimated $37.6 billion in social costs annually (Uri, 2001).
- Chemical contamination. The most effective means of reducing erosion in grain production is no-tillage practices. Unfortunately, these practices depend heavily upon pesticides for weed and disease control. The pesticides that are required in order to reduce erosion from annual crop fields have potential to harm both humans and animals. Recent findings suggest that deformities and population declines of amphibians have been due to pesticide exposure (Sparling et al., 2001; Hayes et al., 2002). In humans, pesticides have been linked to profound learning disorders (Guillette et al., 1998), childhood leukemia (Reynolds et al., 2002), birth defects, shifts in sex ratios (Garry et al., 2002), and reduced sperm counts and quality (Swan et al., 2003). According to a study by the Centers for Disease Control and Prevention (CDC) of chemicals in 9,282 people across the U.S., at least one pesticide was detected in every person studied and the average person carries a mixture of 13 of the 23 pesticides analyzed (Schafer et al., 2004). Clearly, a non-chemical approach to reducing erosion in grain fields is needed, and perennial grain crops are an attractive solution.
- Nitrogen loss and contamination.Globally, only about 30-50% of applied nitrogen fertilizer is taken up by annual crops (Tilman et al., 2002). Due to the lack of year-round vegetative cover, annual cropping systems can lose five times the water and 35 times the nitrogen to leaching as perennial systems (Randall et al., 1997). Not only is lost nitrogen economically wasteful, nutrients lost from annual cropping systems can pollute ground and surface waters, endangering aquatic biodiversity thousands of kilometers distant (Burkhart and James, 1999; Turner and Rabalais, 2003). Some perennials can be fertilized at a rate of 200 kg N ha-1 yr-1 and lose only 1 kg N ha-1 yr-1 to leaching (Andrén et al., 1990; Paustian et al., 1990).
- The promise of perennial grains. The large number of funded SARE grants directed toward expanding use of perennial systems, such as pastures, is a testimony to the importance of perennials to sustainability. Perennial grain crops promise to bring the inherent sustainability of pasture systems (erosion control, nitrogen use efficiency, freedom from pesticides, and reduced input costs) into the millions of acres currently planted to annual grain crops in the North Central Region. Interest in perennial grains is growing due to the potential of large perennial root systems to sequester soil carbon for greenhouse gas mitigation. Furthermore, there is growing interest in using crop residues as biofuels, which could be achieved without exposing soil to erosion only if the grain crops are perennial.
We expect the proposed project to contribute to the following outcomes:
• Increased knowledge of how to grow and breed IWG for use as a perennial grain crop. Through experimentation and interaction with members of the community of practice, we have been improving our methodology for growing and breeding IWG. We expect this trend to continue, which will be evidenced by accelerated progress in the breeding program and improved techniques for growing the crop.
• Increased optimism for the potential of IWG as a crop in the food and agriculture community. Optimism is essential to achieving expanded research, development, and planting of the crop. This optimism will be derived from clear progress in the breeding program and the discovery of reliable techniques for raising a productive crop.
• Increased scientific research with IWG throughout the north central United States. For a new crop to succeed, a diverse team of researchers must be assembled to work on the challenges as they arise. Interest from scientists in many fields is growing, and we soon hope to have a wide array of scientific collaborators.
• IWG is planted on a large acreage for commercial use, which reduces soil erosion on sloping lands. This is an intermediate term outcome. Commercial plantings depend upon the development of improved varieties, agronomic practices, processing techniques, and marketable products. We expect that even with sustained research funding, this outcome is at least 10 years away.
Short-term outcomes will include increased knowledge of how to grow and breed IWG, optimism for its potential as a crop within the food and agriculture community, and an increased number of scientists actively engaged in IWG research.
Intermediate outcomes will include widespread planting of IWG by farmers and commercial use of the grain for food. To evaluate, we will measure indicators of progress toward these outcomes.
In the long term, we anticipate that diverse perennial grain cropping systems could replace more than 50% of current annual crop acreage. Success in breeding, growing, processing, and marketing IWG will serve as a proof of concept for perennial grains in general. IWG will spark interest in and funding for many other perennial grains, including wheat, rice, sunflowers, dry beans, maize and sorghum. Wherever perennial grain crops are planted, soil erosion will be reduced below replacement levels, nitrate loss to ground and surface waters will be reduced by more than 90%, and herbicide contamination will be sharply reduced. Furthermore, reduced input costs will benefit farmers and rural communities economically.